1. Field of the Invention
The present invention relates to a vehicle control apparatus capable of controlling one or more running conditions of the vehicle.
2. Related Art Statement
Japanese Patent Application laid open for public inspection under Publication No. 2(1990)-170561 discloses a vehicle control device including (a) intended-yaw-rate determining means for determining an intended yaw rate of the vehicle based on the angle of operation of the steering wheel of the vehicle; (b) an actual-yaw-rate detector which detects an actual yaw rate of the vehicle; (c) a vehicle-condition changing device which changes a running condition of the vehicle; and (d) vehicle-condition control means for controlling the vehicle-condition changing device based on a difference between the intended yaw rate of the vehicle determined by the intended-yaw-rate determining means and the actual yaw rate detected by the actual-yaw-rate detector, thereby controlling the running condition of the vehicle.
When the vehicle is turning with the actual yaw rate being smaller than the intended yaw rate, the above-indicated conventional control device operates for increasing the braking force applied to the inside wheels; and when the vehicle is turning with the actual yaw rate being greater than the intended yaw rate, the conventional control device operates for decreasing the braking force applied to the inside wheels. In this way, the conventional control device adjusts the actual yaw rate to follow the intended yaw rate.
However, the vehicle may not be controlled by the conventional control device to reach a target position which the driver desires or intends the vehicle to reach, simply by adjusting the actual yaw rate to follow the intended yaw rate. The desired or intended target position corresponds to the angle of operation or rotation of the steering wheel by the driver. Since usually the driver operates the steering wheel in the belief that the vehicle will run according solely to the operation angle of the steering wheel, it can be said that a position corresponding to the operation angle of the steering wheel is a position the driver intends to reach. However, in the event that the vehicle is displaced or slipped in the lateral direction thereof because of, e.g., side wind, the vehicle may not reach the intended target position, even if the actual yaw rate may be adjusted to be equal to the intended yaw rate. Only with the vehicle being slipping in the lateral direction, the conventional control device will not start to adjust the actual yaw rate to follow the intended yaw rate, because the actual yaw rate will not differ from the intended yaw rate in this running state of the vehicle.